The 133 cardinals from 70 countries will be locked inside the Sistine Chapel, where they will vote in secret and silence, a process designed to be both contemplative and free from outside

The smoke billowed out at 9 p.m. Wednesday, some four hours after 133 cardinals solemnly entered the Sistine Chapel, took their oaths of secrecy and formally opened the centuries-old ritual.

The conclave to elect a new pope has officially begun, with a Vatican official calling out ''extra omnes'' and the door to the Sistine Chapel shutting.